Amino-acid insertion in the Meq protein of Marek's disease virus, an avian oncogenic herpesvirus, accelerates tumorigenesis

Meq, an oncoprotein of Marek's disease virus (MDV), regulates the expression of viral and host genes. Meq with an insertion, termed L-Meq, has been identified as a factor that enhances MDV virulence. However, the mechanisms by which the insertion in Meq alters MDV virulence remain unknown. This study investigated the mechanisms underlying enhanced virulence induced by amino-acid insertion in Meq. To examine the differences in the patterns of gene expression by each Meq isoform, we performed RNA-sequencing analysis on tumor lesions in chickens experimentally infected with recombinat MDV harbaring Meq of L-Meq.